During the past year proteins from chikungunya (CHIKV) were used to test genetic vaccine constructs. Efforts were focused on testing the ability of virus like particle vaccines (VLPs)expressing different strains of CHIKV viral proteins to determine their ability to induce potent immune responses in small animal models and non human primate models. Specifically, neutralizing antibodies and T cell responses were measured and the different types of vectors were compared. VLPs induced high levels of neutralizing antibodies and induced a higher response than DNA vectors. Studies were also initiated to determine whether VLPs could be constructed to induce similar types of immune reponses against other viruses of the genus Alphavirus, Family Togaviridae, including Western Equine Encephalitis virus (WEEV), Eastern Equine Encephalitis virus (EEEV), and Venezuelan Equine Encephalitis virus (VEEV). Specific modifications were introduced into vectors expressing the VLPs, resulting in much higher yields of several different alphaviruses than had been previously achieved. Challenge assays with the alphaviruses demonstrated the efficacy of the vaccine in small animal models. In collaboration with Purdue the structure of the the VLPs were studied to provide information for development of more effective vaccines. A CRADA with Merck allowed for continued second generation Chikungunya VLP vaccines and a collaboration with the Dept. of Defense (USAMRIID) was put into place to further the WEEV, EEEV and VEEV vaccine development.